/*
 * jcmainct.c
 *
 * Copyright (C) 1994-1995, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains the main buffer controller for compression.
 * The main buffer lies between the pre-processor and the JPEG
 * compressor proper; it holds downsampled data in the JPEG colorspace.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/* Note: currently, there is no operating mode in which a full-image buffer
 * is needed at this step.  If there were, that mode could not be used with
 * "raw data" input, since this module is bypassed in that case.  However,
 * we've left the code here for possible use in special applications.
 */
#undef FULL_MAIN_BUFFER_SUPPORTED


/* Private buffer controller object */

typedef struct
{
	struct jpeg_c_main_controller pub;	/* public fields */

	JDIMENSION      cur_iMCU_row;	/* number of current iMCU row */
	JDIMENSION      rowgroup_ctr;	/* counts row groups received in iMCU row */
	boolean         suspended;	/* remember if we suspended output */
	J_BUF_MODE      pass_mode;	/* current operating mode */

	/* If using just a strip buffer, this points to the entire set of buffers
	 * (we allocate one for each component).  In the full-image case, this
	 * points to the currently accessible strips of the virtual arrays.
	 */
	JSAMPARRAY      buffer[MAX_COMPONENTS];

#ifdef FULL_MAIN_BUFFER_SUPPORTED
	/* If using full-image storage, this array holds pointers to virtual-array
	 * control blocks for each component.  Unused if not full-image storage.
	 */
	jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
#endif
} my_main_controller;

typedef my_main_controller *my_main_ptr;


/* Forward declarations */
METHODDEF void  process_data_simple_main
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail));
#ifdef FULL_MAIN_BUFFER_SUPPORTED
METHODDEF void  process_data_buffer_main
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail));
#endif


/*
 * Initialize for a processing pass.
 */

METHODDEF void start_pass_main(j_compress_ptr cinfo, J_BUF_MODE pass_mode)
{
	// bk001204 - don't use main...
	my_main_ptr     jmain = (my_main_ptr) cinfo->main;

	/* Do nothing in raw-data mode. */
	if(cinfo->raw_data_in)
		return;

	jmain->cur_iMCU_row = 0;	/* initialize counters */
	jmain->rowgroup_ctr = 0;
	jmain->suspended = FALSE;
	jmain->pass_mode = pass_mode;	/* save mode for use by process_data */

	switch (pass_mode)
	{
		case JBUF_PASS_THRU:
#ifdef FULL_MAIN_BUFFER_SUPPORTED
			if(jmain->whole_image[0] != NULL)
				ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
			jmain->pub.process_data = process_data_simple_main;
			break;
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		case JBUF_SAVE_SOURCE:
		case JBUF_CRANK_DEST:
		case JBUF_SAVE_AND_PASS:
			if(jmain->whole_image[0] == NULL)
				ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
			jmain->pub.process_data = process_data_buffer_main;
			break;
#endif
		default:
			ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
			break;
	}
}


/*
 * Process some data.
 * This routine handles the simple pass-through mode,
 * where we have only a strip buffer.
 */

METHODDEF void
process_data_simple_main(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail)
{
	// bk001204 - don't use main
	my_main_ptr     jmain = (my_main_ptr) cinfo->main;

	while(jmain->cur_iMCU_row < cinfo->total_iMCU_rows)
	{
		/* Read input data if we haven't filled the main buffer yet */
		if(jmain->rowgroup_ctr < DCTSIZE)
			(*cinfo->prep->pre_process_data) (cinfo,
											  input_buf, in_row_ctr, in_rows_avail,
											  jmain->buffer, &jmain->rowgroup_ctr, (JDIMENSION) DCTSIZE);

		/* If we don't have a full iMCU row buffered, return to application for
		 * more data.  Note that preprocessor will always pad to fill the iMCU row
		 * at the bottom of the image.
		 */
		if(jmain->rowgroup_ctr != DCTSIZE)
			return;

		/* Send the completed row to the compressor */
		if(!(*cinfo->coef->compress_data) (cinfo, jmain->buffer))
		{
			/* If compressor did not consume the whole row, then we must need to
			 * suspend processing and return to the application.  In this situation
			 * we pretend we didn't yet consume the last input row; otherwise, if
			 * it happened to be the last row of the image, the application would
			 * think we were done.
			 */
			if(!jmain->suspended)
			{
				(*in_row_ctr)--;
				jmain->suspended = TRUE;
			}
			return;
		}
		/* We did finish the row.  Undo our little suspension hack if a previous
		 * call suspended; then mark the main buffer empty.
		 */
		if(jmain->suspended)
		{
			(*in_row_ctr)++;
			jmain->suspended = FALSE;
		}
		jmain->rowgroup_ctr = 0;
		jmain->cur_iMCU_row++;
	}
}


#ifdef FULL_MAIN_BUFFER_SUPPORTED

/*
 * Process some data.
 * This routine handles all of the modes that use a full-size buffer.
 */

METHODDEF void
process_data_buffer_main(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION * in_row_ctr, JDIMENSION in_rows_avail)
{
	my_main_ptr     main = (my_main_ptr) cinfo->main;
	int             ci;
	jpeg_component_info *compptr;
	boolean         writing = (main->pass_mode != JBUF_CRANK_DEST);

	while(main->cur_iMCU_row < cinfo->total_iMCU_rows)
	{
		/* Realign the virtual buffers if at the start of an iMCU row. */
		if(main->rowgroup_ctr == 0)
		{
			for(ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++)
			{
				main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
					((j_common_ptr) cinfo, main->whole_image[ci],
					 main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
					 (JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing);
			}
			/* In a read pass, pretend we just read some source data. */
			if(!writing)
			{
				*in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
				main->rowgroup_ctr = DCTSIZE;
			}
		}

		/* If a write pass, read input data until the current iMCU row is full. */
		/* Note: preprocessor will pad if necessary to fill the last iMCU row. */
		if(writing)
		{
			(*cinfo->prep->pre_process_data) (cinfo,
											  input_buf, in_row_ctr, in_rows_avail,
											  main->buffer, &main->rowgroup_ctr, (JDIMENSION) DCTSIZE);
			/* Return to application if we need more data to fill the iMCU row. */
			if(main->rowgroup_ctr < DCTSIZE)
				return;
		}

		/* Emit data, unless this is a sink-only pass. */
		if(main->pass_mode != JBUF_SAVE_SOURCE)
		{
			if(!(*cinfo->coef->compress_data) (cinfo, main->buffer))
			{
				/* If compressor did not consume the whole row, then we must need to
				 * suspend processing and return to the application.  In this situation
				 * we pretend we didn't yet consume the last input row; otherwise, if
				 * it happened to be the last row of the image, the application would
				 * think we were done.
				 */
				if(!main->suspended)
				{
					(*in_row_ctr)--;
					main->suspended = TRUE;
				}
				return;
			}
			/* We did finish the row.  Undo our little suspension hack if a previous
			 * call suspended; then mark the main buffer empty.
			 */
			if(main->suspended)
			{
				(*in_row_ctr)++;
				main->suspended = FALSE;
			}
		}

		/* If get here, we are done with this iMCU row.  Mark buffer empty. */
		main->rowgroup_ctr = 0;
		main->cur_iMCU_row++;
	}
}

#endif							/* FULL_MAIN_BUFFER_SUPPORTED */


/*
 * Initialize main buffer controller.
 */

GLOBAL void jinit_c_main_controller(j_compress_ptr cinfo, boolean need_full_buffer)
{
	// bk001204 - don't use main
	my_main_ptr     jmain;
	int             ci;
	jpeg_component_info *compptr;

	jmain = (my_main_ptr) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(my_main_controller));
	cinfo->main = (struct jpeg_c_main_controller *)jmain;
	jmain->pub.start_pass = start_pass_main;

	/* We don't need to create a buffer in raw-data mode. */
	if(cinfo->raw_data_in)
		return;

	/* Create the buffer.  It holds downsampled data, so each component
	 * may be of a different size.
	 */
	if(need_full_buffer)
	{
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		/* Allocate a full-image virtual array for each component */
		/* Note we pad the bottom to a multiple of the iMCU height */
		for(ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++)
		{
			jmain->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
				((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
				 compptr->width_in_blocks * DCTSIZE,
				 (JDIMENSION) jround_up((long)compptr->height_in_blocks,
										(long)compptr->v_samp_factor) * DCTSIZE, (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
		}
#else
		ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
	}
	else
	{
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		jmain->whole_image[0] = NULL;	/* flag for no virtual arrays */
#endif
		/* Allocate a strip buffer for each component */
		for(ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++)
		{
			jmain->buffer[ci] = (*cinfo->mem->alloc_sarray)
				((j_common_ptr) cinfo, JPOOL_IMAGE,
				 compptr->width_in_blocks * DCTSIZE, (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
		}
	}
}
